                            root-is-head-root
                            {:head {:phrasal true ;; only a vp-aux may be the head child, not simply a lexical auxiliary verb.
                                    :synsem {:aux true}}
-                            :rule "s-aux"
+                            :rule "s-aux-passato"
                             :synsem {:infl :present
                                      :cat :verb
                                      :sem {:aspect :perfect
                                            :tense :past}}})
+
+                   (unify c10
+                           root-is-head-root
+                           {:head {:phrasal true ;; only a vp-aux may be the head child, not simply a lexical auxiliary verb.
+                                   :synsem {:aux true}}
+                            :rule "s-aux-trapassato"
+                            :synsem {:infl :present
+                                     :cat :verb
+                                     :sem {:aspect :pluperfect
+                                           :tense :past}}})
+
                    (unify c10
                            root-is-head-root
                            {:rule "s-future-phrasal"

   "imperfetto" {:synsem {:sem {:aspect :progressive
                                :tense :past}}}
   "passato" {:synsem {:sem {:aspect :perfect
                             :tense :past}}}})

(defn fo-ps [expr]
  (parse/fo-ps expr fo))

                                     :cat :verb}})
                   (unify h21a
                           root-is-comp-root
                           {:rule "vp-aux-phrasal-complement-passato"
                            :head {:phrasal false
                                   :synsem {:aux true}}
                            :comp {:phrasal true}
                            :synsem {:aux true
                                     :infl :present
                                     :sem {:tense :past
                                           :aspect :perfect}
                                     :cat :verb}})

                   (unify h21a
                           root-is-comp
                           {:rule "vp-aux-nonphrasal-complement-passato"
                            :head {:phrasal false
                                   :synsem {:aux true}}
                            :comp {:phrasal false}
                            :synsem {:aux true
                                     :infl :present
                                     :sem {:tense :past
                                           :aspect :perfect}
                                     :cat :verb}})
                   (unify h21a
                           root-is-comp-root
                           {:rule "vp-aux-phrasal-complement-trapassato"
                            :head {:phrasal false
                                   :synsem {:aux true}}
                            :comp {:phrasal true}
                            :synsem {:aux true
                                     :infl :imperfect
                                     :sem {:tense :past
                                           :aspect :pluperfect}
                                     :cat :verb}})

                   (unify h21a
                           root-is-comp
                           {:rule "vp-aux-nonphrasal-complement-trapassato"
                            :head {:phrasal false
                                   :synsem {:aux true}}
                            :comp {:phrasal false}
                            :synsem {:aux true
                                     :infl :imperfect
                                     :sem {:tense :past
                                           :aspect :pluperfect}
                                     :cat :verb}})
                   
                   ;; these two following rules are kind of complicated and made more so by
                   ;; dependence on auxilary sense of "avere" which supplies the
                   ;; obj-agr agreement between the object and the main (non-auxilary) verb.
                   ;; Note use of :reflexive below.
